1. Field of the Invention
The present invention relates to devices and processes for improving the ability of an aircraft pilot to maintain control in the event that the aircraft experiences an excessive acceleration force. More particularly, the present invention relates to safety oriented apparatus and methods deploying aircraft airbags. The invention is useful for small aircraft, and is well suited as a modification to existing aircraft.
2. Description of the Related Art
The application of airbags as a safety feature to protect a vehicle occupant from injury (or at least to minimize the prospect of injury to the vehicle occupant) has received considerable attention in conjunction with the automobile industry. An example is U.S. Pat. No. 3,836,168 by Nonaka et al, which shows airbags functionally operable in conjunction with a shoulder harness.
U.S. Pat. No. 5,073,860 by B. K. Blackburn et al recognizes that "it is not desirable to inflate a vehicle airbag under all types of crashes to which the vehicle is subjected", such as "a low speed, non-deployment crash". The determination of what constitutes a non-deployment crash "is dependent on various factors relating to vehicle type", and includes "a large vehicle traveling eight miles per hour hits a parked vehicle", in which case, seat belts are sufficient. This patent provides a time domain vibratory electrical signal having frequency components indicative of a vehicle crash condition. This time, domain signal is converted to a frequency domain signal. The frequency domain signal is correlated, and the airbags are actuated only when the correlation indicates a particular type of crash is occurring. The airbags are not actuated when the correlation indicates that a non-deployment crash is occurring.
U.S. Pat. No. 4,968,965 by M. Naitou et al is directed to apparatus for recording the operation of a vehicle airbag device. An accelerometer provides an output signal, depending upon vehicle acceleration, and this signal triggers air actuation. A decision circuit determines whether or not the airbag should be activated in response to the accelerometer signal.
A number of patents teach the use of a microprocessor in an airbag control arrangement. These patents include U.S. Pat. No. 4,999,775 by K. Muraoka which is directed to preventing the consumption of battery power by airbag diagnostic apparatus from the time the vehicle is shipped until the vehicle is first started; U.S. Pat. No. 5,107,245 by C. Gesper et al which is directed to an automobile restraint system (seatbelt or airbag) that includes a microcomputer to process the output of an acceleration pickup, and wherein the output of the acceleration pickup is inhibited if a fault is detected; U.S. Pat. No. 5,225,985 by M. Okano which uses an acceleration/deceleration sensor to actuate an airbag; and U.S. Pat. No. 5,261,694 by G. W. White et al which relates to a processor-controlled airbag system wherein when a malfunction is detected, the system is reconfigured to substitute one FET for another.
Others have addressed the application of airbags to aircraft, such as in U.S. Pat. No. 4,508,294 by Lorch and 3,218,103 by Boyce. The Lorch patent includes a bidirectionally expanding set of airbags from a hoop around the waist of the aircraft occupant to encapsulate that occupant upon actuation. The Boyce patent likewise teaches use of a relatively complete encapsulation of the occupant of a seat, although it is shown operational in conjunction with a shoulder harness.
German document DE 41 05 821A1 describes an automotive airbag system wherein the rake of a tilting steering wheel is adjusted downward, if it has been set more upright than normal, prior to airbag release.
While the prior art is generally useful for the stated intended purposes, the prior art has failed to provide an aircraft airbag actuation apparatus and method that provides an intelligent aircraft airbag actuation system in which an airbag(s) is selectively actuated by a programmable-type controller that determines whether conditions are appropriate for the activating airbag(s) in the cockpit of an aircraft, and wherein the time of airbag inflation, and/or profile of airbag inflation, is adaptively controlled.